The
Processionary Pine Caterpillar whose usual habitat is in the warmer
regions of southern Europe and North Africa has made an appearance in
Brittany. Known in France as "La chenille du pin", it also lives
in oak trees and has recently moved further north in France and also to
parts of England, Holland and Germany.

The
caterpillar has very nasty, irritating hairs, which it uses as a sting
defence and which cause a rash. Inhaling a hair can give problems
too, especially for anyone with asthma. Dogs can be badly affected
as the irritating caterpillars hairs, rather like nasty fibre glass
strands, can cause great irritation to their mouths and tongues and
sometimes this develops into a really serious problem.

Although
they like warm climates, the caterpillars are active in winter, coming
out at night time even in sub zero temperatures to forage for food.
They return to their nests at dawn where they stay for the day with the
nests absorbing the sun which keeps them warm.

The
caterpillars eventually become moths but whilst in the caterpillar stage
they live in nests called "tents" in the trees. In late March, when
fully grown, they venture out in a long procession, hence their name.
As many as three hundred caterpillars can form a procession and this is
most common in the summer when la chenille de pin looks for ground away
from its tree in order to go into a "puperal stage" .

In August
it comes out from underground having finally hatched out into a moth.
These moths then fly among the fir and oak trees to mate and lay
eggs which eventually hatch out into these caterpillars which
while extremely sociable amongst their own kind are very anti-social to
us.

It is
strongly advised to leave them well alone and also avoid their "tents"
which will undoubtedly contain the irritating hairs. The
caterpillars will initially make several tents before settling down to
their final homes. They like to be in groups and are very
voracious eaters and can strip trees quickly of their needles.

Fortunately
there are some birds that can soon eat up the caterpillars and these
include the cou-cou.

A lot of effort is going into
eradicating the problem in public areas.